Stepdaughter has noticed that my son is gifted... and awkwardly, I think it's her family's 'fault'.

I have one biological son (10) and one stepdaughter (8). I've been with her dad since she was 1, and we are very close and have a good relationship and I have a good relationship with her biological family.My son is gifted, and is naturally adept at logic and knowledge acquisition. The only way I feel I treat him differently than my stepdaughter, intellectually, is in the way I talk to him. He can pick up on subtleties and connections more like an adult than a kid, and so I often explain things to him like an adult, or we talk about topics that are a little more in-depth (science, philosophy, that kind of thing). My stepdaughter, on the other hand, needs things simplified and explained in a more kid-friendly way. I praise them both equally on their strengths and talents, of which they both have plenty.However, my in-laws lean a little more into pandering to my son's intellect. His Christmas gifts from them were stuff like reference books, kids MENSA books, puzzles, engineering and logic games, in addition to the usual chocolate and winter gear and whatnot. My stepdaughter got picture books, dolls, makeup and stuffies. So to me there is a clear difference in how they think of the capabilities of the children.My stepdaughter has started saying things like 'I can be smart too!' and 'You're not the only one that's allowed to be smart' to my son (and to be clear, this isn't, in my opinion, the result of my son being pretentious and certainly not using his intellect as a weapon. He's pretty modest about his smarts and never says or suggests things like 'I'm smarter than you'). It usually comes out when he disagrees with her on something. I've reassured her that she's smart too and has talents he doesn't, but it does seem to genuinely frustrate her at times. In some ways I get it, especially if my son is talking about something she doesn't understand. But I kind of feel like the fact that my son is understood to be high IQ and that her family plays to that strength with their gifts and treatment of him, might be making her feel like he gets special treatment.I was wondering how I should handle this situation. Should I 'have a word' with her family (talk about awkward)? Just ignore it? Give her more praise for her talents and capabilities? Some combination of those? Something else? I don't want her to get a complex for being the 'less smart' sibling, or feeling like she is in my son's shadow. via /r/Parenting http://bit.ly/2GS8lof